More on UIDs

Jeremy Utley wrote:
>>In the book, we create a lot of users and groups. Almost none of them
>>have uids/gids specified. Right now, if a user/group is created without
>>specifying, a uid value > 1000 or a gid value > 100 is used. The LSB
>>says system uids/gids should be below 100. I am proposing a book wide
>>coordinated set of numbers:
>>> *snipped*
>> Actually, my suggestion would be for those system users that are
> associated with network daemons, to use a group to match the port they
> open...i.e. apache assigned 80, ssh assigned 22, etc. No real reason,
> except to try to have SOME rhyme/reason to assignment - those that don't
> do network stuff can be assigned somewhat arbitrarily.
Not a bad idea, but we have several ftp and email servers. I thought
about using the same number for all the ftp servers and the same numbers
of all the mail servers, but that would make the different packages
conflict. I opted for making the numbers of related apps close
together. Also it doesn't work for things like pop (110).
It does work for apache, ssh, and named and I can do that.
The implementation I was thinking about is to add a page to Chapter 2 or
Chapter 3 named "About uids and gids" that sumarizes uid/gid issues. It
should also discuss User Private Groups and mention the interaction and
possible update of /etc/login.defs.
-- Bruce